Sexual Response

The peak of sexual excitement is reached during the third phase. Involuntary muscle contractions, heightened blood pressure and heart rate, rapid intake of oxygen, sphincter muscle contraction, spasms of the carpopedel muscles in the feet, and sudden forceful release of sexual tension characterize the orgasmic phase.

For men, orgasm generally climaxes in the ejaculation of semen, which contains millions of sperm. Ejaculation consists of two steps. During the first phase, called the emission phase, seminal fluid builds up in the urethral bulb of the prostate gland. As the fluid accumulates, the male senses he is about to ejaculate. This is often experienced as inevitable and uncontrollable.

For women, orgasm also consists of rhythmic muscle contractions, in this case of the uterus, at about the same pace as in men. Tightening of the woman's muscles puts pressure on the man's penis and assists in male orgasm.

For both sexes, barring the presence of some form of sexual dysfunction, orgasm is an intensely pleasurable experience. Indeed, some see it as the most pleasurable experience possible.